


underwater

by Imaginary_Capable16



Series: scars (and other things I wish I could hide) [1]
Category: Transformers - All Media Types, Transformers: Prime
Genre: F/M, Gen, I came up with this in the middle of the night, I didn't mean to make Acree a bitch but that's just how it turned out, Minor Violence, Oops, Optimus is concerned, She's a badass, Sirens, arcee is skeptical, as usual, bulk is oblivious lol, bumblebee is a sweetheart, enchanment, it's more like a short story at this point, look what you made me do, mermaids?, oh boy, optimus has no idea what to do, ratchet is having none of your shit today optimus, sirens song, the kids make minor appearances, this is the dumbest concept ever, this is the longest one-shot I've ever written, this isn't fluff but neither is it angst
Language: English
Status: Completed
Published: 2020-03-15
Updated: 2020-03-15
Packaged: 2021-03-01 03:55:38
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 10,341
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23148859
Author URL: https://archiveofourown.org/users/Imaginary_Capable16/pseuds/Imaginary_Capable16
Summary: Optimus Prime, it seems, is always exhausted. Hoping to cure this, he retreats to a semi-secret location to think and hopefully relax. It does not go as planned.
Relationships: Optimus Prime & Original Character(s), Optimus Prime & Original Female Character(s), Optimus Prime/Original Female Character(s)
Series: scars (and other things I wish I could hide) [1]
Series URL: https://archiveofourown.org/series/1664026
Comments: 4
Kudos: 26





	underwater

**Author's Note:**

> Oh dearest Lord  
> So I started writing this on a whim and it turned into a several thousand-word one-shot. it's basically a short story at this point. I'm honestly super pleased with it though. Again, I don't know how accurate this is to any kind of mythology. I tried to stay away from the stigma that Sirens and Mermaids were always these pretty little things with bright tails and instead could kill a dozen men in the blink of an eye. It was super fun to work with, and I don't think I've ever been so tired after writing a small book lmao.  
> This is literally the dumbest concept I've thought up ever but like, it was so much fun writing this, probably the most fun I've had writing in a while. Please enjoy this monstrosity I wrote in less than a week lol

Optimus was exhausted. Then again, when wasn't he?

The last energon mine raid had been particularly difficult. There had been more Decepticons than anticipated, and the mine was larger and more complicated. 

They (and by they, Optimus meant everybody save for Ratchet) returned with some sort of injury, varying in seriousness: Bumblebee sustained a deep gash to his leg and limped his way into the base, Arcee clutched her arm, dripping Energon, Bulkhead had several dents in his chassis, and Optimus himself was covered from helm to pedes in scratches. 

After Ratchet had done his best to patch everyone up and the children sent to their respective homes, Optimus stood in the middle of the base, contemplating if he should take some time to himself for once. 

Concluding that if needed, Ratchet would radio for him, Optimus walked over to the Groundbridge controls. The medic was in re-charge, along with his scout and wrecker. Arcee remained awake, and Optimus asked her if she was up to main the Groundbridge. 

She nodded and walked over with him. After he plugged in the coordinates, she pulled the lever, and the vortex of teal, blue, green, and yellow erupted in the tunnel. 

He nodded goodbye to Arcee, who smiled and watched her leader as he walked through the portal. 

The Groundgridge opens in a cave, on the coast of the ocean in the state he believes the humans call California. He'd discovered it after a mission to an energon mine nearby, and after disposing of the wrecks of the Decepticon drones, he wandered past the cave. It was hidden from human view, big enough to fit him and three other bots, and quiet. And that was what he liked most. 

His back strut creaks and groans as he stretches, allowing his cables and pistons to relax. It's a ripple in the water in front of him that causes them to tense once more. 

It wouldn't have been all that concerning. The open ocean, as he'd been told by Miko, held a menagerie of creatures, and he was more than likely to find some here. But the water is clear, and no fish swim beneath its surface. Could it have been a drop of water from the cave's ceiling? No, it doesn't seem that way. 

And there was another, near a rock in the cave. His left servo switches into his blaster, and his other poised near his helm, ready to call Arcee for a Groundbridge. Optimus calls out a hesitant "Hello?" into the cave that echoes back at him. 

For a moment, nothing happens, and he's mostly sure he's still in high alert mode and got all worked up for nothing when a head- a human  _ head  _ pops out from behind a rock. It's the same rock he saw the ripples by, and he realizes now it couldn't have been a coincidence. 

It's female, from what little he can see. Her hair is short, cut above her shoulders and dripping wet. Her eyes are sharp, though she stays a safe distance from him, and he realizes he's still pointing his blaster. 

He lowers it, transforming it back into a regular servo, and crouches where the water meets the ground. "Hello," he repeats, not sure what else to say. 

She looks back at him, tilting her head to the side, as though contemplating his words. It occurs to him suddenly that she might not speak English, but he does know that is the most common language here. 

She pulls herself up fully onto the rock, and his intake falls open. 

She does have a human head but follows it most definitely not human. 

It is not legs, but rather a tail, a fishtail it seems. Its scales range from dark green to brown, to pale green and back again. A dorsal fin runs from below her shoulder blades to the tip of her fluke. Pectoral fins of the same color and spotted here and there along her tail, and they twitch in the open air.  There are more frills on her head, where ears would have been. They flutter whenever a gull cry echoes outside and keep her short hair out of her face.  The scales from her tail run up along her chest and on the underside of her arms. There are frills on those too, though he can see they lay flat. There are even scales on her face. They are few in numbers, but there are a few patches here and there. They seem to follow no specific order or correlation.  The slits on her neck, he realizes, are gills. He has seen pictures of fish and sharks from the children, and he knows they serve the purpose of filtering Oxygen in the water for breathing needs. 

Optimus watches as she opens her mouth, her gills and vocal cords shifting as an ugly screech come from her lips. He winces at the sound, watching as she continues to shift her vocal cords until a clear "Hello," comes out in response. He kneels there in shock.  She clears her throat, looking concerned. "I apologize, I'm not used to this." 

"There is no need. You have a language of your own?" He figures he should be asking a very different question, somewhere along the lines of 'who are you, how long have you been here, and  _ what  _ are you?' But he believes those would be inconsiderate at the moment. 

She nods in response to his question. "And you speak English?" 

"Yes, Ratchet-" He should most definitely  _ not  _ be telling a stranger how Ratchet helped program several languages spoken on Earth into their processors. "Yes, among others," he supplies. 

It is her turn to nod, though she pauses for a long minute. "You come here often." 

It is not a question, and he does not particularly like the fact that she knows this. "I do, it is-" he pauses, searching for the right word. "Quiet, peaceful. A nice change from normalities." It occurs to him that he doesn't know how she knows he's been here before, and it concerns him slightly. 

Her tail half in the water twitches, sending ripples through the still surface of the pool. He watches it with curiosity and a hint of wariness. The frills and spines move as though each one has a mind of their own, the effect resembles a plant in the wind. 

"Tell me," she says, "Where do you come from? Did humans build you?" 

"No, no we came here." 

"On purpose?" 

"Our ship was damaged, and this planet has a resource we need." 

"So you come from the stars?" She looks out of the cave, and though the sky outside is light, he gets the feeling she is trying to see the space beyond. 

"Yes, a planet called Cybertron." 

"I would like to hear why you are here, do the humans see you?" 

He ponders answering this for a moment. "A select few, they keep us hidden. There have been a few accidents, however." 

Her lip curls upward in response to the last part, as though she knows what kind of accident and has had experience with such things. "You never explained why you are here, I would like to hear your stories if you do not mind." 

He doesn't, and before he knows it, he is giving her the whole speech he'd given to the children, to nurse Darby, to Fowler, and other military personal. The whole nine yards, as the humans say. She listens with rapt attention, there are no questions asked, and her eyes do not falter from his, though he cannot say the same.  Her gaze is not uncomfortable, that is not the word he is looking for, it is more like she is looking through him, as though she can see the cogs and pistons in his chassis and helm. 

When he finishes with the story, she remains silent but nods when he goes silent. Optimus shifts his position into a sitting one and kicks his legs out in front of him so that his pedes are half-submerged in the clear water of the cave. 

She pushes herself off the rock and swims forward, cutting effortlessly through the water as she stops near his pede, examining it. Another flick of the tail and she rests on the surf to the left of him, stretched out and arms crossed. Her head rests atop of them, and the frills on her head remain still. The dorsal one flattens, as though it is trying to hide.  "Is your kind dangerous? I have seen your defense mechanism, how often do you use them?" 

Optimus thinks to Megatron, to the rest of the Deceptions, to the war on Cybertron, to the now war on Earth, and answers. "We can be, some of us more than others." She nods, and he asks the question in return. 

"Some of us. Our tradition his to hunt for food, and what meals consist of vary for all of us." She twitches her tail and Optimus watches the frills shrink down to reveal spines. They line down her back, along her forearms, and even on the sides of her tail. She thrashes it, and he watches as one of the spines embeds itself in the dead center of a rock on the opposite wall. "There are other methods used to defend ourselves, crueler, more traditional." 

He gives her a questioning look. "What do you mean?" 

The frills fold back into place, and she settles on the rocks again, still. Optimus watches her tail with wariness. "We all possess the ability, some call it a Siren's song. We enchant, anything within earshot has no chance. Some drown their victims, others play with their food." 

"Food?" He does not like where this conversation is going. 

"When I said meals vary for many of us, that is what I meant. An old tradition of ours is to hunt humans. They are the easiest to enchant and live in large quantities." 

"Have you enchanted a human before?" He asks with hesitance. 

She looks up at him, something like pain and an apology in her eyes. "I have not killed a human in some time, it doesn't sit well." 

Optimus watches as she tracing the crevice of a rock with her finger, and dares to ask another question. "Can you sing to us? Cybertronians?" 

She shrugs, and part of him breathes a sigh of relief. "I do not know, I haven't tried and I do not intend to. All species are different, and thus, require a different song. Usually one can base it off of a similar animal, but I have not ever heard of your kind before, nor worked with sentient machines." He cracks a small smile at that. 

"And what about you? Where do you come from?" 

She turns her head to look back to the mouth of the cave. "The Ocean, it is all our kind knows, though some have ventured inward through rivers and lakes. Some cannot take the freshwater though." 

"Have you?" 

She shakes her head and lays flat again. "I stay where the pack goes." 

"There are more of you?" 

She nods and takes a pebble in her hand, folding it between her fingers. "I have many brothers and sisters. I am one of the oldest, thus given the role of protecting the young." 

"Do you stay close to the coast?" He does not know why he is asking all of these questions, but somehow, it is nice to meet another species with a similar story: avoiding humans, staying hidden, protecting the young, and undoubtedly making decisions for the better of the group. 

"During mating season, yes. Though we tend to gravitate to the more uncivilized areas." 

"For obvious reasons." 

That earns him a laugh. It is more of a giggle than anything, but her teeth show and when he peers closer, he notices they are filed down to a point. Whether by natural or hand, he does not care to know. 

He looks away. 

She notices and stops laughing. Her face grows solemn, as though she knows what has seen and what he thinks. "I should go." She pushes herself off the rocks, backing into the water. 

"Wait," he calls, and she freezes. "I have... quite liked speaking with you." He pauses, not sure why he wants to continue talking with her. "Do you have a family?" 

She looks at him, something between suspicion and hopefulness. After a moment of silence, she swims back to the rocks of dry ground and returns to the same position as before. "I have many brothers and sisters, they are all the family I need. And what about you? Do you have any young?" 

Optimus starts at the question. Bumblebee, he thinks, is the closest thing he has to a son. He is the youngest of the team, and he'd taken a special liking into him during the war. "Of a sort. I have a team and they are the closest thing to a family." 

"I do not know your name." 

"Optimus Prime, and you?" 

She pauses, eyebrows furrowing. Her gills flutter and her throat shifts again, and when she opens her mouth, another screech echoes in the cavern. It is different than the first, but he does not know how. 

She looks up at him, vocal cords shifting again. "It does not translate well to English or any other human language for that matter. Most of our words do not, I apologize." 

"There is no need." He is quick with his response. "Can one learn this language?" 

Her jaw drops a bit and her eyes widen. "You wish to learn our language? Why?" 

He shrugs, "I am curious. You have learned English, perhaps I could learn your's if it made you more comfortable. We too have our language. I have been told it resembles ancient Egyptian Hieroglyphics." 

She stares at him incredulously, and he wonders if he took a step too far. The corners of her mouth turn upwards, a smile without teeth. "You are far more pleasant to speak with than I first assumed Optimus Prime." She pauses again. "I don't know, to be honest. No human I know has managed to learn it." 

"I am quite far from human." 

This time, she smiles with pointed teeth. "Yes, I suppose you are." They sit there in silence, listening to the waves lap against the rocks, and the occasional call of gulls outside. 

The Siren breaks the silence with a snort and looks up at him. "Would you like to hear a story? My pack thinks it rather funny." 

He nods, leaning back against a rock and listens to her speak. The tale  _ is  _ rather funny, and though he looks up many of the species she mentions off-handedly on the fly, he follows along rather well. She laughs to herself a few times, and when she finishes, he offers to share a story of his own. 

She nods, shifts to lay on her back gazing up at the ceiling, and gestures for him to begin. And they stay like that for some time, at least an hour, perhaps more, trading stories of varying topics. She tells a story of how her pack mistook a Whale Shark for a submarine; about the time they raced some dolphins from coast to coast; the time they played hide-and-seek in a coral reef and had their game interrupted by a group of SCUBA divers. He tells the story of how Bulkhead ran into a bunch of power lines when they first came to Earth. She does not know what they are, and after he explains it, she bursts into laughter. It makes him smile. They both do, and Optimus feels more at ease than he has all month. 

After they've quieted, and he can see the sun beginning to set against the backdrop of a painted sky, if occurs to Optimus that perhaps Arcee is wondering where he is. 

She notices his change in demeanor. "I take it your family would like to see your return." 

"They may be worrying, they tend to do that, for good reason." 

She nods and rolls onto her stomach again, chin in her hands. "Well then, Optimus Prime, I wish you well. I am happy to have known you." 

He pauses, suddenly disappointed that this is the only time he will see her. "Do you come here often? Will I see you again?" 

She smiles coyly at him. "Perhaps, perhaps not." 

"Wait." He pulls out a communicator, a spare Ratchet insists he keeps on him at all times, and after the last incident, he can't say he blames the old medic. He kneels, holding it out in his servo. "Take this, if you are ever in danger, I am merely a click away." 

She regards it with an emotion he cannot quite place. He has gotten better at reading human expressions since coming to Earth, but sometimes he must ask the children for help. He wishes one were here with him now, to help dissect what this woman is thinking. But part of him believes that no one will ever know, and he is okay with that, in a way. 

She takes it in her hand; she can barely wrap her fingers around it and regards it with newfound curiosity. "Thank you, and you will find me if you so desire." 

He does not ask for details, he feels as though she will not give them. The Siren swims over to a pair of rocks and wedges the communicator between them. Optimus hopes it is out of the way of the rising tide. 

She nods to him one last time and sinks below the water's surface, eyes open. A twist of the tail and she is at the mouth of the cave, swimming out into the brilliantly colored water. 

Optimus reaches up to his helm. "Arcee, I require a Groundbridge." 

~ ~ ~ ~ ~ 

Optimus does his best to put the encounter to the back of his processor for the remainder of the week, but he cannot manage it. His team makes note of it, and ask him several questions, though they do not pry. Ratchet, however, very much pries. 

"You've been distant all week! More so than you usually are. I understand you want to see Megatron back to his old self, but sometimes people cannot be saved Optimus." 

He knows what the medic is referring to: the fight he'd had with Megatron the day after the cave incident. It was neither a win nor a loss, some convoluted area in between. It had been on his processor, among certain other things (or someone for that matter) since it happened, and he needs a break.  _ Again.  _ He can't remember the last time he'd taken a break aside from the time or two at the cave. 

"Do not worry old friend, I understand." Ratchet gives him a look that he thinks the children would call exasperation. 

Against his better judgment, he does go to the cave. It is late, well past midnight and the children are home, and everyone else, save for Ratchet (what a surprise) is in recharge. 

As he walks over to the Groundbridge controls, plugging in the set of coordinates that have been bouncing around in his processor for at least a week. Ratchet narrows his optics at him, and grumbles and he marches over. "Comm if you need anything, stay safe." 

Optimus nods in thanks and walks through the vortex, and into the cave. 

He doesn't know what he should expect. Perhaps she somehow knew he was coming and is laying at the edge of dry ground, giving that coy smile he knows he should not want to see. Or maybe she is hiding behind a rock like the first time. 

What he does walk into, however, is none of those, nor anything he expected. 

The cave is full of Sirens. 

As the Groundbridge closes behind him, all heads whip in his direction, and in a split second, he is faced with dozens of snarling faces, all with mouths of pointed teeth and tails equipped with spines and deadly accuracy. 

The hissing they produce echoes in the walls, and he watches nails of the few closest to him grow into talons. Frills fold back to reveal spines, and all around him, all he can see are angry, hissing men, women, and children. 

His servo jumps up to his helm, ready to call Ratchet when a loud, commanding shriek echoes over every hiss. They all grow quiet as a single figure cuts through the water with ease, coming to rest on a rock. He recognizes her in an instant. 

"Optimus Prime, we meet again." 

He exhales in relief, and sends a warry, small smile to her. She grins back with pointed teeth, and screeches to what he assumes is her pack. They all, after the smallest moment of hesitation, back off. 

Frills replace spines, snarls are replaced by curious faces, and talons become fingernails once more. If Optimus had any doubts that these people were dangerous and could tear him limb from limb, he does not anymore. 

She gestures with a sweeping arm to the cave. "I apologize, my family is warry, all for good reason." 

"Do not apologize, I understand." 

She returns the arm to her side and leans more against the rock, staring up at him. "Why have you come? Are you in danger?" 

He shakes his helm, suddenly bashful as to the true reason he came. "I merely would like some company, this week has been-" He searches for the word. "Difficult, to put lightly." 

She hums and nods, and one of the smaller Sirens swims up to her, gently poking her tail. The woman looks down, and for a moment, they speak in their native language, and Optimus cannot understand a word. 

Half of the pack watches him, all with varying emotions, and the other half pays a close ear to the child and the woman. 

They converse for a moment more, then the woman looks up at him, smiling. "She says hello, in the simplest of terms. She would like to know who you are." Optimus starts and shifts his gaze to the younger of the two, who is looking at him with a childlike sense of curiosity. "Would you mind if I told them? It may ease their concern, I will translate as much as I can, not all here speak English." 

"Of course, my permission was not needed." 

"It is your story, not mine." 

"Even so." She smiles, nods, and shifts into her native language. 

He watches with mounting astonishment as they all turn to gaze at her. Optimus does not know much about their manners, but he can tell they give her their undivided attention. She is respected here, looked up to as a leader and a mother figure. He wonders if his team feels the same way about him. 

Occasionally, the stray head of a Siren will turn to look at him, sporting the same curiosity he is experiencing. When she finishes, a good number of them begin calling in their native language, addressing and fighting for her attention. 

She laughs, throwing her head back. "They have many questions for you, do you mind?" 

He shakes his head, laughing a little to himself. "Not at all, can you translate them?" 

"Most, paraphrasing is a wonderful thing." This gives her a low, rumbling laugh that she grins at. They communicate again, and she turns to him again, snorting with laughter. "They-" another snort of laughter, "They want to know if you can swim." 

Optimus looks around at the scaley faces gazing at him intently. They seem completely serious, and it's this portion of the situation that makes his smile grow. She seems to sense his humor and lets out another giggle. "We are capable, though I cannot do it well. Shall I explain the complications of rusting?" 

She shakes her head, still grinning, and relays the answer, or one close to it, to her family. They seem disappointed, and it makes it all that much more humorous. 

A few more questions are asked, and Optimus even offers up some of his own. The woman is their translator, and more than once has to pause to best give an accurate question or answer to the other side. 

It is somehow, quite fun. The most enjoyable time he has had in a long time. There is always a sense of danger in their base, no matter how much joy and noise the children bring, it is always in the back of his processor. He knows he must be the first line of defense if something were to happen, and it weighs on him often. 

Here, however, is very different. He is out of his element, and though it is disconcerting, it is refreshing. He knows that if someone were to happen upon the cave, this family would handle it with such agility, he wouldn't have time to act himself. 

To be under the care and protection of others is not something he's used to. 

It is late, the sky is beginning to lighten on the line of the horizon, and Optimus realizes he has been here far longer than he anticipated. He rises to his pedes in the middle of a story of his that his Siren is translating (when did he begin to think of her as his?) 

Everyone stops to look at him, he dares hope some seem disappointed. "It is late, or early, by human standards, I should be going." 

His Siren nods and raises a hand in farewell. "You are welcome here Optimus, my people do not see you as a threat to them." 

He notices her wording and smiles a bit to himself, before raising his servo in goodbye, and coms to no doubt worried Ratchet for a Groundbridge. 

~ ~ ~ ~ ~ 

The call comes a month later. Deception activity has been at a low, Energon stocks are supplied, the children are healthy, and everyone is unharmed. 

The beacon pops up on the communication board and all heads- human and Autobot alike- turn toward it. Ratchet looks up nonchalantly, but his expression quickly changes. "It's one of ours, Optimus did you leave your spare in-" He pauses, squinting at the pair of coordinates. "California? On the coast somewhere. The signal is botched, must be underground." 

Optimus stops dead in his tracks. There is a sudden sense of panic in his spark. "Ratchet, prepare a Groundbridge. Arcee, Bumblebee, will you accompany me?" 

The medic gives him a look of surprise. "Optimus, what-" 

He raises a servo as his two companions walk over, sporting equally confused looks. "If you please Ratchet, a Groundbridge. I will fill you in later." 

The children, playing some game on the balcony, wave goodbye, unaware as to what is happening on the floor. Ratchet pulls a handle, and the green, blue, yellow, and white vortex opens. 

Before they walk through, he pulls the two aside. "I ask you this: as the humans say, keep an open mind. We will not be the only ones present." 

Bumblebee chirps in affirmation and confusion, and Arcee nods, transforming, servos into blasters. 

They exit the Groundbridge, all with blasters aloft, fanning out as they enter the cave. Optimus looks around hesitantly, spark pounding; the cave is empty, there is no sign of struggle, but something feels off to him. It occurs to him that he does not know what name to call, she gave her name in her native language, but it is not something he can imitate. 

"Hello?" He calls out instead. "I have come as you asked." Arcee gives him a look as she scans the cave for attackers. 

Then, to his left, the water shifts, as though something beneath it has moved. Arcee and Bumblebee snap to attention, blasters pointed to the center of movement. Optimus throws up a restarlueus, transforming a blaster into a servo, giving a silent order to stand down. "I apologize, we mean no harm, I swear it." 

This time, he sees her approach, and he realizes that he has never really seen her swim before. It's a fascinating thing, like nothing he's seen before. It has an air of something unknown, something he shouldn't be seeing. The fins along her tail float freely, and he almost can't see the spines hidden in them. 

Her head rises out of the water, arms pulling herself halfway up onto the rocky ground. Optimus crouches, reaching down and ignoring the astounded looks he's getting from his teammates. "Hello." That seems to be a reoccurring theme in their conversations. 

She looks at him, then her gaze shifts to the other two, and the frills on her head flare upwards. Muscles in her arms tense and all down her body, frills and fins stand on end, though he cannot see the deadly spines yet. He hopes that is a good sign. 

"They are family," he supplies, referencing their earlier conversation. "They will do you no harm." The woman- Siren- he corrects, does not look so convinced. "You called me here." 

She nods, still giving warry looks to Arcee and Bumblebee. "There are men outside the caves." Arcee scoffs and Optimus can practically sense her rolling her optics. "They walk with one of your own." That is not good. 

"Describe him." 

"Tall; sleek; grey. I do not know much about your kind." 

Arcee takes a step forward, blasters still charged and Optimus watches the Siren's gills flair, he makes a mental note to stay between the two. "Silas, I don't know anyone else who's willing to partner up with Cybertronians." 

Optimus rises from the water's edge. "But what he wants remains unknown." 

"On that account, I may be able to assist you." Optimus turns to face the woman in the water, and he highly doubts Arcee and Bumblebee have looked away. "I believe they search for something, I will only be a moment." And then she pushed herself off of the rocks and disappears into the water, he does not see her leave. 

Bumblebee lets out a series of bees and whirs, gesturing to the water. Arcee hums in response, transforming one blaster into a servo and resting it on her hip. 

"A friend, we have met before, she intends us no harm." 

"So why do I have a feeling she's lying?" 

Optimus gives her a look. "Arcee, I have been in this cave alone, if she had intended anything but peace, she would have executed such plans." 

"Odd choice of words there." Another look served. 

The water at the entrance of the cave ripples and the sound of transforming blasters meets his audio receptors. As the ripples draw closer, he makes out the shape of the Siren cutting through the water, and she is dragging something large. It's when she hoists its halfway onto the rocks that he realizes what is it, or rather who: a Decepticon drone. Even Arcee is silent at this revelation. 

It is dead, that much is clear. From the hole in his chassis to the numerous dents and scratches everywhere else, Optimus wonders what happened. Seawater pours out of cracks and crevices, there are a few strands of kelp that cling to him as well. 

"There are many more outside the caves, perhaps a dozen, more even. It is like a graveyard, even the fish do not go near them." A pause seems to echo in the cavern, everyone seems at a loss for words. "If the men are searching for these, they will find them if they venture to the water. I fear they will find my sisters and brothers as well." Problem after problem seems to arise. 

"I understand. Will you take my scout to see these men? I wish to confirm their identity." Bumblebee takes a step forward, making the wise decision to de-activate his blasters. 

She spares him a look, eyeing the place where his blasters disappeared. "If you wish. Follow me, scout." 

Bumblebee does as asked, chirping as he wades into the cave water, hugging the cavern walls where it is most shallow. He does not look entirely comfortable, it is not often they find themselves treading through water. Their bodies can take it, Optimus himself has been submerged completely a time or two. Though rust can be a problem, he recalls half-listening to Ratchet list a few ways he can remedy the process. 

They disappear around the corner, and Arcee does not move her optics from the mouth of the cave. "I don't like this." 

_ Which part,  _ he thinks, though he does not voice it. "I am aware." 

"We don't even know who she is, or  _ what  _ she is!" 

"I do," He says before he can think to stop himself. 

Arcee's helm snaps toward him. " _ How?"  _

He shrugs. "We've met once or twice." She gives him a look of suspicion. "Arcee, she means us no harm, I would bet my spark on it." 

Arcee opens her intake to give him a quick-witted retort when Bumblebee wades around the corner. He beeps quietly, optics flashing toward the water. Optimus notices the woman swimming beside him, in a sort of protective matter. He wonders what happened outside the cave, and what Bumblebee said to get her to trust him, enough where she makes sure he doesn't fall into the seemingly bottomless cave. 

His scout reaches the dry ground, picking a piece of kelp off his pede, and launches into a report. 

Their guess, it seems, was correct. Silas is here with his men, at least two scores of them. They've been walking along the coast for some time, Bumblebee says he didn't see any sort of cars with them. The worst part, he tells them, is that they carry guns, at least half of them do. He does not recognize them, perhaps a new technology recently developed in their hidden labs that seem to be always just out of reach. Whatever they are, Bumblebee makes it very clear he does not like the looks of them. 

Then comes the part Optimus knew was coming: Starscream. 

Even if his Siren doesn't know how to identify most Cybertronians, Bumblebee can and does. He reports the certain Decepticon walks along the coast with them, occasionally offering a comment. Though MECH does not enjoy his company (that much is clear) they need him for something, so they keep him close. 

Arcee, as is her nature, begins immediately creating a plan. "We need out of this cave, find some high ground. We can call Buklhead for backup, who knows what these people have now, and Starscream won't help the situation." 

Bumblebee chirps in agreement, and Optimus looks to the Siren. She looks back. He kneels at the water's edge, listening absent-mindedly to his team. "Do you know a way out of this cave undetected?" 

"I do, do your people trust me?" 

"They will have to, lead the way. Arcee, Bumblebee," He calls, rising to his pedes. The two turn away from their conversation, glancing at each other before Following Optimus as he wades in the water, keeping to the sides as Bumblebee did. 

The Siren swims beside him at a slow, leisurely pace that he knows she must be keeping for him. When he reaches the mouth of the cave, a rocky shore greets him, steadily down the coast, it turns into sand. There is a hill above the cave, giving them cover from prying eyes, and Optimus keeps low and he crawls out of the water. It is a dune, there are several of them, all covered in grass. The rocky ground beneath him is slippery with seawater, and he does his best to keep his balance. Arcee and Bumblebee follow his lead, the first keeping a warry optic on the Siren in the water. 

She remains still, tail swishing back and forth under the water to keep her in one place. Optimus supposes it is her kind's way of treading water. "Stay close to the dune, when the ground turns to dirt and you can see trees, make your way toward your people, they will not see you coming. If you would like," She adds hesitantly, "I can keep an open eye from here." 

He nods. "That would be most appreciated, we will follow your advice. Thank you." 

She nods. "Be safe." With that, she sinks below the waves and swims out to the open ocean. 

Optimus gives the signal, and Bumblebee leads the way, scouting ahead as he does best. He follows, and Arcee brings up the rear, watching both of their backs. 

They keep low, crouching behind the dunes and if he is quiet, he can hear the distant chatter of men. 

The winds from the ocean blow the grasses and bushes around him too and fro, making them dance. Ir mesmerizes him for a moment before he realizes that this is a mission, and his teammates need his full attention. 

Optimus can suddenly feel the ground change from hard rock, to soft dirt. Bumblebee picks up on this too and quietly chirps. 

"Proceed," he whispers in response. 

The three of them past behind the group of MECH soldiers and Starscream, silent as a grave. At a point, the Decepticon turns his helm and all three of them stop dead in their track, not moving a cable. 

Silas hurries him along, clearly impatient, and Optimus breathes a sigh of relief. They continue for a moment longer, until they are behind the last men in the group, and straighten from behind the dunes. 

He hears Acree charge he blasters, followed closely by Bumblebee. He orders them to hold fire. He will not kill these men unless necessary. 

Starscream is the first to notice out of all of them, and he sputters in shock as he turns around, pointing a rocket in their direction. "Prime!" 

His name causes MECH to turn as well, and after their initial reaction of surprise, they too charge their weapons. 

Silas steps forward. "Optimus Prime, we meet again." 

Optimus can't help but make a comparison to the way the leader of MECH says his name and the way she says it. "Silas," he offers in greeting. 

"You're outnumbered." 

"A matter of perspective." 

He looks around mockingly. "Are you hiding another Autobot around here somewhere?" Optimus doesn't answer, only preps his blasters. "Tell you what," Silas begins, gesturing to his men. "You leave, take your friends with you, and we'll let you. No guns, no missiles, no nothing." 

"I cannot allow that to happen." 

Silas sighs, as though he's disappointed him. "If you say so, fire at will gentlemen." 

They do. 

Optimus involuntarily steps in front of his teammates as the men closest to him who only hold- by human standards- normal guns, open fire. The metal bullets bounce off of his armor with little consequence, merely a few scratches, but then one of the men in the back lowers to one knee, aiming a much larger weapon Optimus has not seen before. 

Arcee jumps out in front of him, swatting at the humans, respecting his wishes not to kill them, and his scout does the same. 

Optimus sees the man aim Bumblebee and has little time to think before he is launching himself in front of the scout as a canister hits him square in the chassis. 

He goes down instantly. 

Whatever hit him runs an electric current through his body, and it causes him to convulse. The pain it causes is unreal, it is as though he is being stabbed in every part of his body simultaneously. His systems are overloading, error messages and warnings echo in his audio receptors, and he wonders if this is how he joins the All Spark, through human intervention. 

It is then that he hears is, a resounding, unholy,  _ angry  _ screech that echoes across the water. 

Everyone stops, and Arcee takes the opportunity to rush over and yank the casing that is running electricity through his limbs out of his chassis and throws it to the ground. He gasps, shaking off the pain and bumping his volume receptors. 

Everyone has turned to gaze out into the open ocean, even Starscream is confused as to what is happening, Primus,  _ Optimus  _ doesn't know what is going on. 

The screech echoes again, this time, it has a different emotion to it. It is still angry yes, very much so, but there is something else behind it. A sort of challenge, a calling to arms. 

Optimus then realizes who is behind the sounds, and it hits him like a missile. "No," he whispers gently, and both of his teammates turn to look at him, understanding in an instant what he means, and who he refers to. 

But he only has eyes for the woman who rises from the water, skin glittering in the afternoon sun, a coy smile on her lips, and hair thrown back. 

It is them she opens her mouth, and all of Silas's men stop in their tracks. Even the man himself doesn't move. 

Optimus doesn't understand for a moment what is happening. He still has control of his limbs, and his Back Strut has not straightened as though pulled from a string. 

The four Cybertronians stare dumbfounded as the men drop their guns, turn their shoulders toward the ocean, and being to walk toward it. No, he realizes, they are not walking toward the ocean, but toward the Siren floating in the shallows. 

They all watch, not enchanted, but mystified, as the first few men step into the water. They do not hesitate in their step, they too, seem to only have eyes for the Siren. 

He understands now why she called it a song, and why they call it an enchantment. 

Unexpected fear grips him as the man wade farther in, they do not look as though they intend to stop. Optimus has half a mind to stand between them and the Siren. He doubts it would change anything. 

She reaches out her hand as the closest man as he wades in. He's less than a foot away, and when he's close enough, he too reaches out. 

As he places his hand in hers, her smile grows, and the expression is almost tender. Optimus feels a spike of something like jealousy in his chassis and he half wonders where it came from, but the other half knows exactly why it's there. What pulls him from his feelings happens in less than a second, and he almost misses it. 

The change is sudden: one minute, the Siren is gazing tenderly into the eyes of the man she is holding, the next she has tightened her grip, and yanked him into the water. 

Her face is no longer beautiful, at least not by human male standards. Frills stand on end, pointed teeth shine in the sunlight, and she shrieks in the water as the spell breaks. 

The men slowly come to their senses, but in the next moment, she thrashes her tail and three of them drop into the waves without so much as a sound. 

Optimus does not think she can take down forty men, but she does not need to. The water to her left and right begins to boil, and one by one, the men vanish below the surface. They do not have time to scream. 

Sirens jump from the water and tackle the men. Some use their spines, others gruesomely bite into the uncovered flesh of their necks and faces. A few use their talons, cutting through whatever protective layers the men of MECH wear like paper. 

Optimus kneels there in awe, shock, or horror, he can't decide. Maybe a mix of all three. It is over in less than a minute, it feels like far less than that to him. 

The sea calms, and she and her pack slip below the surface without a trace. The only thing that hints to a group of men being on this beach is their guns in the grass and footprints in the sand. 

It is haunting. 

The air is quiet, between the four of them, neither has said a word. Starscream tries to sputter some sort of sentence, but changes his mind and take a running head-start. Optimus hears him transform and boost his engines. None of them try and stop him. 

Arcee is the first of them to move. "Ratchet, we need a Groundbridge." An affirmative sound comes from the other end of their comms. 

Optimus doesn't quite know what to, and he does not like this feeling, it's not something he's used to. At least he is not alone in this situation. His two teammates seem to be in equal amounts of shock as him, he wonders offhandedly how many questions Ratchet will ask when he returns, and if he will be able to answer them. 

They walk into the base in silence, all three of them. Ratchet is waiting at the controls, absent-mindedly telling them that Bulkhead has taken the kids for a joyride, under strict instructions to bring them back if anything happens. 

Optimus nods, watching the seawater drip from his armor. 

"You need a decontamination bath, all three of you. What have I said about getting in the ocean?" 

"Not to do it," Arcee mumbles, and Bumblebee chirps the same answer. 

Ratchet nods, and gestures for Arcee to go take her decontamination bath, and then turns to Optimus. "Did you find your spare?" 

"No, it was a distress signal." 

Ratchet starts. "From who?" 

"A friend, there is no concern needed old friend, everyone is well." 

Their medic shrugs. "If you say so

Bulkhead returns with the children, they jump from his alt mode with shouts and talk up to their little alcove in the base. Ratchet groans, unhappy to have the quiet of his base shattered, and Optimus lets go of a weary smile. 

A few hours pass, Optimus waits them out in his berth room as Bumblebee takes his turn, and when the children are being escorted home (Rafeak rides with Miko) he walks back into the main room. 

"Ratchet, a Groundbridge if you please." Ratchet raises an optical ridge but does not ask any questions. Optimus has a feeling he'll get them when he returns. 

"Be careful, I don't want to send Arcee after you." 

"I always am, old friend." Ratchet snorts and mutters something under his breath, Optimus does not hear it. 

The vortex opens, and he walks through, looking back to see the medic watching his departure. He nods and emerges in the cave. 

The gentle lapping of waves against the rock and the blowing winds outside are the only thing he hears. It has grown darker outside- the sun is setting, and the sky is painted in brilliant colors shades of red, orange, yellow, and blue. 

There is no sign of his Siren or any other for that matter. "Hello," he calls out, it's at least the fourth time he's said that in a conversation with her, it's growing old. There is no response. "Hello?" He calls again, louder this time. Still nothing, now he is worried. Perhaps he should walk outside the cave and call again, perhaps she cannot hear him. But what good will that do if she is underwater? 

He has half a mind to call Ratchet for another Groundbridge when the water at the mouth of the cave ripples unnaturally. The familiar glint of a green tail and short hair is the only thing that comforts him. 

He kneels on one knee, anticipating her rising from the water. Her head emerges, and her expression is cautious, as though it is unsafe to be here. Perhaps it is. "Hello." 

"You should not be here."  _ Hello to you too,  _ he thinks, it is something Miko would say. "I must go, it's dangerous." 

"Wait," He pauses, looking for something to say that will keep her here, just for another moment. "I came to ensure you are safe, how is your family?" 

She gives him a look and hesitantly settles on the rocks. The frills on her back settle, and he takes that as a good sign. "They are well, they send their good wishes." 

"Tell them I send mine as well. Thank you for coming to my aid." 

"You would've done the same, it was the least I could do." 

"You are terrifying," he says without a second thought.  _ Primus, well done.  _ "I apologize." 

She winces slightly, he almost doesn't see it, then shrugs. "It has been some time, I almost worried they would be too much." 

The realization dawns on him. "You called your pack in?" 

"They were more than happy to assist, they have taken a liking into you, as have I. Besides, from what I have learned recently, these men were not the best of humans." 

"No, no they were not." He notices their use of past tense. "May I ask you a question?" She nods, crossing her arms on the rocks. "You mentioned to me before that each species requires a different song, what do you sing about?" 

She looks ready to flee, afraid of him almost. It makes his spark clench unhappily. "It varies from, it is hard to explain through your words." 

"English?" 

"Yes, we have words you do not, and you have words we do not." He wishes he has more time to ask about learning her language, it fascinates him. "Unless you have experienced it, I do not know how to tell you." 

He ponders this statement for some time, an idea coming to his processor. "Perhaps that is a possibility." 

She doesn't seem to catch on for a moment, and Optimus watches as the realization dawns on her face. This expression he recognizes: it is terror. "No, absolutely not, I refuse." Her tail flicks, and she's poised to flee. "Goodbye Optimus Prime, I hope your kind finds the peace they are looking for." 

"Wait, please. If I will never see you again, there is no harm in it. I wish to hear it, only once. If you truly will not, I will respect your choice and wish you well on your way." He doesn't know exactly why he wants this. Not only does it fascinate him, but he wants- no that is not the right word, perhaps curiosity is the closest word that describes this feeling. 

He's warry to know what pulled those men into the water without so much as a breath of hesitation. He wants to know what they heard: words of promise or something else? She says she can sing of peace, and part of him wonders what it would be like to know that in absolution. It has been so long since Cyerbertron was not at war, he has almost forgotten what it feels like. To put his mind at ease, even if for a few seconds, would be an unforeseen blessing. 

She looks up at him, half settling back onto the rocks. "It may take a moment, it may not even work." 

"You have all the time you need." 

"You misunderstand, I do not know a single person or creature who has heard the song and lived. Perhaps someone in my pack does, but I do not recall them speaking of it. Optimus, I do not know what effects this will have on you, I do not know if I can stop it." 

"I am not human, we have discussed this." He says with humor, a poor attempt to lighten the mood. 

She does not seem to find it amusing. "There is no going back after this, I do not know what you will see or hear, I cannot filter that. If something happens to you and I cannot stop it-" She breaks off, looks down, and clears her throat. "I would never forgive myself. You are a close friend, even if we have only known each other for a week at most." 

He looks at her, really looks, and sees, among others, fright. It strikes him suddenly that he does not truly know what happened to those men this morning, he does not know what they saw or what they heard that compelled them toward that body of water, and part of him never wants to know. 

The part  _ needs  _ to know, needs to know if he can experience that same bliss of ignorant happiness. It has been so long- too long- since he has felt anything close to it. 

"It is not your fault if anything befalls me, I chose this." 

"Then I will ask you once more: are you absolutely sure you want this?" 

He nods. 

Optimus doesn't know what to expect when she opens her mouth to sing (to enchant, really), but the harmony that comes out is almost normal. It sounds like it is coming from an ordinary human. 

She shifts from tone to tone, melody to melody, and some sound more pleasant than others. Some sound like the music Rafael listens too, Opera, he believes, is what the boy calls it with a blush on his cheeks, though Optimus does not know why. Other's sound less than ideal, like an untrained singer, but all have one thing in common: they do not have words. 

His spark sinks, thinking truly that he will never hear what those men did, but something changes in her voice (he will never be able to pin down what it was) and his helm snaps upward. 

He can hear  _ words.  _

It hits him like a train. Well, not really hits, per se, it rolls over him. Like a gentle caress or a wave. How ironic. 

The words he hears are not coming from her mouth, he cannot see it working around the promises bouncing around in his processor. 

She speaks of Cybertron, not Decepticons or Autobots; of Megatronus, not Megatron; of Orion Pax, not the war-torn Optimus Prime; of the time before the war, of peace. She sings of health and happiness, so much of it that Optimus is throughout engulfed. He can see his family, his friends, the children, all in good health, and in as much happiness and peace as him that it fuels his own. 

Cybertron is whole, a living planet rather than a desolate wasteland. He can see Solus Prime, his friend, and mentor in the archives. He can see his other friends too, they are not torn down from the war, they are healthy and whole. 

He hears words of humankind, of how they are now at peace as well. Agent Fowler is well, Nurse Darby cares for Jack, they are both well, and the other two laugh, their smiles stretching across their entire faces. 

_ It doesn't get any better than this _ , he thinks, and he is so happy he could join the Allspark and have no regrets and-

"Stop!" A command, one of the sharpest he's heard in a very long time, rings out in the cavern. 

Optimus resets his optics, and see's the woman floating in the water, tail swishing back and forth. She looks pained, and her eyes are wet, and not from the cave water. 

He then looks down, suddenly curious as to why he can feel the current on his armor, and he realizes he is aft-deep in water. 

His pedes are grounded well, they are holding onto the last section of rock before it drops off into the unknown. Another step and he would've sunk. 

Optimus shakes his helm, trying to banish the dazed feeling that is clinging to him. The Siren places a gentle hand to his armor plate. "I am so sorry." 

"There is nothing to apologize for." He says as sort of instinct. 

She looks down, bashful. "What did you see?" 

"My family, my planet, friends well and whole again, much of what I hope will return." 

"I have given you false hope, I-" 

"No, I have had this hope for centuries, long before I met you or came to this planet. This is by no means your fault." He pushes himself up onto the ground with a shaking servo, though he isn't entirely sure why. "Thank you, it was... indulging, fascinating. I do not know the word for it." 

She nods. "I understand, and I thank you for knowing me, it has been a pleasure. Your family must wonder where you are." 

"I told them I was coming here." 

"Then they will be even more concerned." 

The corner of his derma quirks up and he rises to his full heights, watching as the water drips off of him. Ratchet will not be pleased. "Will you leave this place?" 

"Most likely. People will hear of this incident, whether or not we want them to. They will swarm this coast looking for answers, and as humans are, they will not stop until they find them. Men fear what they do not understand, they feel threatened by it. Enough men have died today, I do not wish for more." She pauses, noticing his downcast expression. "We will return, given time, when these humans have forgotten. Until then, we will find a new stretch of coast, or perhaps return to the open ocean again." 

He nods, acknowledging the undeniable logic she presents. The real false hope he harbors is wanting her to stay here, within reach where he can easily come to her aid if she needs it. He doubts she will, she's more than capable, but to know she is going somewhere he cannot follow is a little more than disheartening. 

"Then I wish you well, give my regards to your family. If you ever require my assistance, you know where to find me." Both of their gazes turn toward the hidden communicator wedged between the rocks. Optimus suddenly has a sense of foreboding, as though he knows what she's about to do. 

His Siren swims to the rocks, pushing them aside with ease and pulling out his spare. She holds it in her webbed hands for a moment, staring down at it, before moving back to her previous position, not meeting his optics. "I do not like human behavior, it is predictable. As they say, history repeats itself, and I believe that will come to pass. The chances are slim, but still possible, but I believe they will find this cave, and if they look hard enough, they will find this. That puts both of our species at risk, and I will not let this happen." She holds it up to him. "Take this with you, if you truly need me, you will have no trouble finding me." 

Optimus hates that he is faced with sound logic. He wants to find another place to hide it, a safer one. But he too knows humans, they are persistent creatures, and he has no doubt they will look for his Siren and her family. 

He cannot put another species at risk, he simply won't. 

So he doesn't argue when he reaches down to pluck the communicator from her small hand. "I am sorry." 

"I am too." 

They do not say what they are sorry for, he doesn't think he knows fully what exactly they mean by this exchange, but it is enough. 

This time when he reaches up to request a Groundbridge, she watches him leave; watches the vortex open in the cave, and watches as Optimus looks over his shoulder as he walks through. 

She raises her hand in farewell, slowly sinking below the surface. 

When Optimus walks back into base, Ratchet is the only one on the main floor. The others, he assumes, are in recharge or taking their respective children home. 

After closing the Groundbridge behind him, Ratchet gives him a sweeping look. "You smell like the ocean, take a decontamination bath before recharge." 

Optimus nods and looks solemnly at the empty Groundbridge generator. Ratchet notices, and doesn't say anything, merely leaves him to his own devices. He doesn't ask what happened, and Optimus does not tell. 

~ ~ ~ ~ ~ 

The children hear about the incident, whether through friends, news media, or elsewhere, they learn about it. They bounce theories back and forth, search articles on Rafael's laptop, and whisper about the mysterious disappearance of forty men. 

They bring the bots into the conversation once or twice, asking for their opinions. Arcee and Bumblebee trade knowing looks and change the subject quickly. Bulkhead participates, he does not know what happened on the coast of California, and they do not plan to tell him. The fewer who know the better. 

Ratchet knows, however. He coaxed it out of Optimus when he saw his old friend is being more distant than usual, and the leader tells it all. All except the last conversation he had with her in the cave. He's less shocked than Optimus would have thought, though he supposes the medic has seen and heard stranger, they all have. 

Through the children, he hears of another story. 

A remaining group of men, ones from the recently disbanded organization of MECH, swarmed the docks along the coast of Virginia. There were a dozen of them, and none returned to civilization that night. The only person who saw what happened was a worker up in an observation tower. 

He claims that the men had grabbed a bright, glowing blue gem, and were hauling it to a truck when they all stopped, straightened, and turned toward the water.

Then they began to walk. 

The worker claims they all jumped into the ocean, one by one and swam out, but to what, he could not see. He claims the sea thrashed, that waves swallowed the men, and they all disappeared one by one. 

The only thing that remained of their existence was the empty truck and the open cargo container. 

Articles claimed he was insane, drunk, stoned, or all three. But the minute Optimus hears the story, he knows what happened, and who was behind it. 

He lets the children's imagination run wild and keeps the secret of her to himself. 


End file.
